Full-time score from Greenhous MeadowMillwall kicked off life in League One with a goal each for strike partners Steve Morison and Lee Gregory - and a spirited display that saw The Lions fight back from a 1-0 deficit to claim an excellent awayday win.
After a goal-less first-half the game sprung into life when Shrewsbury took the lead through James Collins in the 54th-minute. But Millwall, inspired by the outstanding Fred Onyedinma, were back on level terms five minutes later with a close-range finish from Morison and then wrapped up victory in the 67th-minute thanks to Gregory's clinical conversion from the penalty spot.
Following the disappointment of relegation last season manager Neil Harris, installed on a permanent basis during a summer that also saw a major change in the playing personnel, was determined to get the new campaign off to the best possible start with a positive performance at the newly-promoted Shrews.
Handing full debuts to Tony Craig and Morison, with fellow summer signings Jordan Archer and Shane Ferguson on the bench, The Lions started with a 4-4-2 system, looking to use the pace and skill of widemen Lee Martin and Onyedinma to craft scoring opportunities for the new strike pairing of Morison and last season's top scorer Lee Gregory.
The Lions, roared on by 1,547 fans making a first-ever visit to Greenhous Meadow, began crisply and in the opening two minutes a neat move started with right-back Shaun Cummings' clipping a ball through to Gregory on the right, but his attempted cross to Morison was blocked.
On six minutes Onyedinma jinked his way past two defenders and whipped over an inviting cross that home keeper Jayson Leutwiler eventually gathered after acrobatically punching clear the initial delivery at full stretch.
After a quiet opening, Shrewsbury twice failed to capitalise on free-kicks in near identical positions on the right flank. Martin Woods' first floating delivery on 10 minutes picked out Tyrone Barnett, who headed wide at the back post and his second a couple of minutes later saw keeper David Forde collect comfortably. Forde then released the ball quickly to Gregory, deep in the opposition half, but the frontman was harshly penalised for a foul and a promising move came to an abrupt halt.
The Lions breathed a collective sigh of relief on the quarter hour when Jean-Louis Akpa Akpro worked his way past Cummings and his inviting hanging cross was headed narrowly over by Barnett.
However it was Harris' men who then enjoyed their best spell of the opening half and in the 18th-minute Shaun Williams forced a fine save from Leutwiler, who palmed away the midfielder's left-foot low free-kick as it arrowed towards the back of the net.
If that was a good save, better was to follow just three minutes later when the Shrews' keeper denied Onyedinma at full stretch after Millwall's pocket rocket had bamboozled the home defence with some neat play on the edge of the area and hit a stinging low shot.
Leutwiler was called into action once more on 32 minutes, this time getting a touch to tip the ball over after Martin's free-kick took a wicked deflection and was heading goalwards.
Mark Beevers came closest to breaking the deadlock 10 minutes before half-time with a powerful header from Martin's deep cross only to be thwarted by a goal-line clearance from Abu Ogogo.
Neither team made any changes at the start of the second-half, but there was a change to the scoreline within nine minutes of the restart when the home side took the lead courtesy of a close range finish from Collins at the back post after the Woods and Barnett had created the opening on the left.
However Millwall fashioned the perfect reply and were back on level terms within four minutes, Onyedinma was the provider with a great driving run that took him into the penalty area and to the byline, where his low cross picked out Morison and the finish was as crisp as it was accurate.
It was a great response from The Lions and things got even better on 67 minutes when Onyedinma again caused problems to the home defence, this time with a superb threaded pass through to Morison, who was upended as he collected the ball just inside the penalty area. Up stepped Gregory to lash the ball into the roof of the net from the resulting spot-kick as Millwall turned a 1-0 deficit into 2-1 lead within the space of eight minutes.
A flurry of bookings followed in quick succession as the home side seemed not only in danger of losing the game, but their discipline too, with three bookings in as many minutes for Woods, Akpa Akpro and Tootle for rash challenges on Williams, Onyedinma and Martin.
Lions boss Harris introduced Ferguson for Martin on 73 minutes and the visitors continued to press in search of a third goal. It was from Ferguson's left-foot free-kick that Ed Upson squeezed in a 75th-minute shot on goal that was well saved after working the ball from one foot to the other and back again.
Upson was played in by Gregory a couple of minutes later, but on this occasion dragged his crisp drive narrowly wide of the target.
Shrewsbury nearly hauled themselves level with four minutes remaining, which would have been harsh on a composed Lions' outfit, but sub Liam McAlinden's flicked shot flew inches over the bar.
Despite a slightly generous six minutes of injury-time, Harris' men kept their shape and wound down the clock expertly to ensure that the new season got off to a perfect start.
Shrewsbury: Leutwiler, Tootle, Sadler, Woods, Grandison, Goldson, M.Woods (Brown, 67mins), Collins (McAlinden, 78mins), Ogogo, Barnett, Akpa Akpro (Whalley, 74mins). Subs not used: Burton, Lawrence, Ellis, Vernon.
Bookings: Ogogo (61mins), Woods (69mins), Akpro (72mins), Tootle (73mins)
Scorer: Collins (54mins)
Millwall: Forde, Cummings, Beevers, Craig, Webster, WIlliams, Upson, Martin (Ferguson, 73mins), Gregory (Marquis, 84mins), Morison, Onyedinma. Subs not used: Archer, Cowan-Hall, Nelson, Powell, Philpot.
Booking: Williams (65mins)
Scorers: Morison (59mins), Gregory (67mins, pen)
Ref: C Breakspear
Att: 6,671 (away 1,547)